The cluttered Old Greenwich home scorched by arson last week showed telltale signs of a longtime hoarding problem and reveals insight into the lives of the two people who lived there, including one who killed himself, according to experts.

For Dean and Barbara Verboven, the son and mother who resided at 46 Havemeyer Lane, a hoarding situation, which devolved until the inside of the house became nearly impassable, ended in tragedy Oct. 2. Barbara Verboven, 69, was badly burned during the blaze and remains in critical condition at Bridgeport Hospital. Emergency responders found Dean Verboven, 42, dead with a gunshot wound to his head. The state medical examiner’s office ruled his death a suicide.

The investigation into who set the fire is ongoing.

Friends of the Verbovens have said little about Dean and Barbara, and family members have not publicly responded to the tragedy.

But Dr. Blaise Worden, a staff psychologist with the Anxiety Disorder Center and Center for Cognitive Behavioral Therapy in Hartford, said the small amount of evidence available from the home provides information about what may have been happening inside.

“It’s typically the setup we see with people who have what we call hoarding disorder,” Worden said. “They tend to be pretty isolated.”

“I’d place my bet that it’s been going on for quite a while,” Worden added.

People with hoarding disorder differ slightly from hoarders who also suffer from obsessive compulsive order, in that OCD hoarders tend to hoard more “bizarre” materials, including their own bodily waste, and exhibit other OCD-type behaviors, like obsessive hand washing, according to Worden. Officials have released no information about any bizarre hoarding materials that may have been inside the home.

Though little information has been made public about what was inside the Verbovens’ home, Worden said individuals dealing with hoarding disorder often hold onto vast amounts of memorabilia, photographs, newspaper clippings and other personal mementoes.

“They have very exaggerated beliefs about the possessions they have,” she said.

First-floor windows remain boarded up at 46 Havemeyer Lane, blocking any view inside, but the outside of the residence is in a state of disarray. Empty cans and bottles dot the lawn, a garbage-filled Dumpster sits to the side of the house, and an enclosure in the yard is piled high with debris.

Worden said that even if a person in the affected residence isn’t doing the hoarding him or herself, he or she may have trouble keeping up with the pace of the collected material.

Many hoarders also live for a long time inside their cluttered homes.

“To some degree, they like the clutter,” she said. “In general, they tend to be pretty resilient people.”

People who suffer from the disorder also often have other problems, such as depression or a past trauma in their lives, and have very difficult life circumstances, as well as other hoarders in the family, she said.

“We don’t often have [situations] like this, with abrupt suicide,” she said of Dean Verboven. “It sounds like something was very disturbing to him.”

Though it is unclear when the hoarding began in the Verbovens’ home, Barbara’s husband, a former Greenwich police officer, died in the early 1990s, and Barbara has been wheelchair-bound for about five years, according to neighbors.

Dr. A. Dennis McBride, Milford’s health director, who is a nationally recognized expert on hoarding, said elderly hoarders often become unable to cope with the sheer amount of materials that have entered the home.

“You can find people who are sort of clean hoarders,” he added.

Those types of hoarders will often have meticulously organized collections and boxes stacked to the ceiling but not mounds of trash or decaying pet corpses seen in other hoarding cases, McBride said.

McBride recalled one particular case he was involved in where a rat died in the narrow path free of hoarding materials inside a woman’s house.

“That disturbed her,” he said.

Family members of hoarders sometimes live a lifestyle that is the exact opposite of their hoarding family members by becoming exceptionally clean or organized, he said.

“Many families have gone through a lot of angst with this,” he said.

McBride said he has seen hoarding cases end in tragedy, as with the Verbovens.

About 1 percent to 5 percent of the population hoards, according to Worden.

The center has had success treating the problem through cognitive behavioral therapy while assisting hoarders with organizational skills, she said. But the hoarder must first accept help.

“The more you try to force them to do things, the more defensive they become,” she said. “It’s very much an uphill battle.”

McBride called hoarding “very underappreciated as a national problem.”

“It’s one of the most perplexing and frustrating problems those of us in public service have to deal with,” he said.